Single-powder photographic developers stabilized with metaboric acid



Patented Jan. 19, 1954 SINGLE-POWDER PHOTOGRAPHIC DEVEL- OPERS STABILIZED WITH METABORIO ACID Donald J. Kridel and Edwin S. Wiitala, Rochester, N. Y., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing. Application June 26, 1952, Serial No. 295,834

This invention relates to single-powder photographicdevelopers, and more particularly to a single-powder developer in which the ingredients of the developer are intimately mixed in the form of dry powder with powdered metaboric acid (H302), as a stabilizing agent to prevent disadvantageous interaction between the or anic developer component and the basic component ofthe single-powder mixture.

Heretofore Single powder developer mixtures have been prepared and packaged which contain an organic silver halide developer component or mixtures of such components, including monomethyl p-aminophenol sulfate (elon or metol), hydroquinone, p-aminophenol hydrochloride, p-

aminophenol sulfate, pyrogallol, parahydroxy phenyl glycine, catechol, diaminophenol hydrochloride, and others, with an alkali component, a stabilizing component, an oxidizing preventer and an antifogging component. The alkali component may be the stable hydrate of an alkali carbonate, a desiccated alkali carbonate, an alkali metaborate, or an alkali sulfite. Generally the stable alkali carbonate monohydrate is preferred. The oxidation preventing compound may be potassium bromide or iodide. Stabilizing components for such a single-powder developer are disclosed in Patent 2,384,592, of September 11, 1945, and include maleic anhydride, salicyclic acid, al-

kali metabisulfite, benzoic anhydride, orthobenzoic sulfimicle, phthalimide, and phthalic anhydride. .The latter has outstanding stabilizing properties particularly in the presence of either sodium carbonate or borax and has been em-- ployed considerably more than the other stabilizers mentioned in the patent.

. While the stabilizing efiect of the phthalic anhydride is very good, it has been employed most successfully in developer compositions having as thealkali component either sodium carbonate or sodium sulfite,-or mixtures thereof. Less success has been attained in the case of the important class of developers containing sodium metaborate as the alkali ingredient.

to temperature eiiects with these basic substances and: form gas under sufiicient pressure to distend the hermetically sealed can in which the 7 Claims Also the presence or. phthalic anhydride in the single-powder de-i veloper involves other considerations which are.

an improved stabilizing agent which makes possible the production of single-powder developers having improved stabilizing characteristics containing as the alkali ingredient, sodium metaborate.

In accordance with the present invention these and other objects are attained by employing metaboric acid (H1802) as the stabilizer, instead of other previously known stabilizers, in suchsingle-powder developers which contain both organic developer components and basic components.

We have found that metaboric acid does not have the objectionable characteristics possessed by phthalic anhydride. Because metaboric acid is less acid than phthalic anhydride it does not react as easily or as violently as phthalic anhydride with alkali carbonates or alkali sulfites such as sodium carbonate and sodium sulfite. In this respect it is noted that the pH of phthalic anhydride is about 2.4 while the pH of metaboric acid is about 5.4 at 3% concentrations. 'Metaboric acid is especially suited as a stabilizer and has characteristics required for a stabilizer. It

is acidic, relatively colorless, odorless, and stable and, has no deleterious action photographically.

A preferred embodiment of the present inven-' tion involves the use in the single-powder photographic developer mixture of either the stable hydrate of an alkali carbonate or also a desiccated alkali carbonate. The alkali carbonate hydrate appears to be more stable in the presence of an organic developer than a comparable quan-,

aminophenol hydrochloride, p-aminophenol sulfate, pyrogallol, p-hydroxyphenyl glycine, cats-' chol, diaminophenol hydrochloride, and suitable;

mixtures thereof, a stable alkali carbonate, such as sodium carbonate monohydrate; and metaboric acid, and may contain the other well known ingredients normally present in a developer, such as sodium sulfite and potassium bromide, the normal and known function of the alkali sulfite being that of preservative, lessening the oxidation in solution of the organic developing agent; while the known function of potassium bromide is that of a restrainer particularly inhibiting fog formation in the development of the silver image. If sodium metaborate is employed its moisture content should be not more than 35% and preferably be about In compounding the developer mixture, one may proceed by first mixing th stabilizer and the basic component, adding and mixing therewith the developing agent, which is followed by incorporating the other ingredients. However, one can mix all the ingredients together at the same time without causing any diiliculty.

The following examples will serve further to illustrate developer mixtures within the scope of th invention and will also indicate the proportionate quantities in which the respective components can be mixed together in a dry form to make up such single-powder photographic developer mixtures.

Example 1 Grams Elon (monomethylp-anuno phenol sulfate) 3.1 Anhydrous sodium sulfite 45.0 Hydroquinone 12.0 Sodium'carbonate monohydrate 81.3 Potassium bromide 1.9 Metaboric acid 4.2

Example 2 Grams Elon 1.5 Anhydrous sodium sulfite 22.5 Hydroquinone 6.3 Sodium carbonate, desiccated. 15.0 Potassium bromide 1.5 Metaboric acid 1.0

Example 3 Grams Elon 2.2 Anhydrous sodium sulfite 96.0 Hydroquinone 3.8 Sodium carbonate monohydrate 57.5 Potassium bromide 5.0 Metaboric acid 3.4

Example 4 Grams Elon 2.5 Anhydrous sodium sulfite 30.0 Hydroquinone 2.5 Sodium met-aborate (10% E) 10.5 Potassium bromide 0.5 Metaboric acid 4.7

Example 5 Grams Sodium sulfite 50 Sodium carbonate monohydrate 54 Potassium bromide 1 Metaboric acid 2.2 Pyrogallol 6.3

Example 6 Grams Sodium sulfite 50 Sodium carbonate monohydrate 54 Potassium bromide l Metaboric acid 2.2 "Catechol 5.5

Example 7 Grams Sodium sulfite 50 Sodium carbonate monohydrate 54 Potassium bromide 1 Metaboric acid 2.2 p-Hydroxyphenyl glycine 8.4

Example 8 Grains Sodium sulfite 50 Sodium carbonate monohydrate 54 Potassium bromide 1 Metaboric acid 2.2 p-Aminophenol sulfate 7.3

Example 9 Grams Sodium sulfite 50 Sodium carbonate monohydrate 54 Potassium bromide 1 Metaboricacid e 2.2 p-Aminophenol hydrochloride 7.3.

Example 10 Grams Sodium sulfite 75 Sodium carbonate monohydrate 30 Potassium iodide .01 Metaboric acid 2.2 Hydroquinone 9 Elon 1 Example 11 Grams Elon 10.0 Anhydrous sodium sulfite. 1 100.0 Sodium metaborate 20.0 Metaboric acid 4.0

Example 12 Grams Elon 7.5 Sodium sulfite, desiccated 100.0 Metaboric acid 1.1

Example 13 Grams Sodium sulfite 96 Sodium carbonate monohydrate 56 Potassium bromide 5 Metaboric acid"--. 1.7 -;Hydroquinone 8.8- Elon 2.2

Example 14 Gram; Diaminophenol hydrochloride 34.6 Sodium sulfite 59.2 Potassium bromide 3.2 Metaboric acid 2.9

Eramplefi G amg Elon 3.0 Sodium. sulfite, v 45.0 Hydroquinone 12.0 Sodium carbonate monohydrate 80.0 Potassium bromide 0.6 5-methy1benzotriazole 0.06 Metaboric acid 1.4

metically sealed. ns at .120 F- ior proloneedl periods, to be unimpaired in developing proper- ,5 g I ties and to give a solution comparable in color to solutions prepared from such chemicals not previously mixed. No expansion, of the package in which the compositions were stored was noted as contrasted to the developers similar in composition except that phthalicranhydride replaces ,the metaboric acid of the present invention.

We claim: I

1. A stable single-powder photographic developer composition containing an organic silver halide developer, a stabilizing agent comprising metaboric acid and a soluble, stable, and photographically compatible basic ingredient selected from the group consisting of alkali borates, sulfites and carbonates.

2. A stable single-powder photographic developer composition containing an organic silver halide developer, a stabilizing agent comprising metaboric acid, an antifoggant, and a soluble, stable, and photographically compatible basic ingredient selected from the group consisting of alkali borates, sulfites and carbonates.

3. A stable single-powder photographic developer composition containing an organic silver halide developer, sodium carbonate monohydrate;

and metaboric acid.

6 4. A stable single-powder photographic. developer containing an organic silver halide developer, alkali carbonate; an alkali sulfite and metaboric acid.

5. A stable single-powder photographic developer containing an organic silver halide developer, an anhydrous alkali carbonate, an alkali sulfite and metaboric acid.

6. A stable single-powder photographic developer composition containing an organic silver halide developer, sodium sulfite, sodium metaborate, and metaboric acid.

7. A stable single-powder photographic developer composition containing an organic silver halide developer 5-methyl benzotriazole and metaboric acid.

DONALD J. KRIDEL. EDWIN S. WIITALA.

Number Name Date Rogers Aug. 5, 1952 

1. A STABLE SINGLE-POWDER PHOTOGRAPHIC DEVELOPER COMPOSITION CONTAINING AN ORGANIC SILVER HALIDE DEVELOPER, A STABILIZING AGENT COMPRISING METABORIC ACID AND A SOLUBLE, STABLE, AND PHOTOGRAPHICALLY COMPATIBLE BASIC INGREDIENT SELECTED FROM THE GROUP CONSISTING OF ALKALI BORATES, SULFITES AND CARBONATES. 